Transparency is meaningless for asynchronous ports, so we assume
transparent == false to simplify the code in this case. Likewise,
enable is meaningless, and we assume it is const-1. However,
turns out that nMigen emits the former, and Verilog frontend emits
the latter, so squash these issues when ingesting a $memrd cell.
Fixes#2811.
This essentially adds wide port support for free in passes that don't
have a usefully better way of handling wide ports than just breaking
them up to narrow ports, avoiding "please run memory_narrow" annoyance.
When converting a sync transparent read port with const address to async
read port, nothing at all needs to be done other than clk_enable change,
and thus we have no FF cell to return. Handle this case correctly in
the helper and in its users.
When extracting read register from a transparent port that has an
enable, reset, or initial value, the usual trick of putting a register
on the address instead of data doesn't work. In this case, create soft
transparency logic instead.
When transparency masks land, this will also be used to handle ports
that are transparent to only a subset of write ports.
Like wide port support, this is still completely unusable, and support
in various passes will be gradually added later. It also has no support
at all in the cell library, so attempting to create a read port with
a reset or initial value will cause an assert failure for now.
Since the packed cell doesn't actually support wide ports yet, we just
auto-narrow them on emit. The future packed cell will add
RD_WIDE_CONTINUATION and WR_WIDE_CONTINUATION parameters so the
transform will be trivially reversible for proper serialization.
Such ports cannot actually be created or used yet, this just adds the
necessary plumbing in the helper. Subsequent commits will gradually
add wide port support to various yosys passes.
This is going to be used to store arbitrary priority masks in the
future. Right now, it is not supported by our cell library, so the
priority_mask is computed from port order on helper construction,
and discarded when emitted. However, this allows us to already convert
helper-using passes to the new model.
There will soon be more (versioned) memory cells, so handle passes that
only care if a cell is memory-related by a simple helper call instead of
a hardcoded list.
cell_inputs and cell_outputs retain cell pointers as their keys across
invocations of setup(), which may however be invalidated in the meantime
(as happens in e.g. passes/opt/share.cc:1432). A later rehash of the
dicts (caused by inserting in ModWalker::add_wire()) will cause them to
be dereferenced.
Among other problems, this also fixes equality comparisons between
SigSpec by enforcing a canonical form.
Also fix another minor issue with possible non-canonical SigSpec.
Fixes#2623.
When an expected logger error pattern is unmatched, the logger raises
another (hidden) error. Because of the previous ordering of actions,
`logv_error_with_prefix()` would inadvertently invoke `yosys_atexit()`
twice, causing a double-free.
This change set contains a number of bug fixes and improvements related to
scoping and resolution in generate and procedural blocks. While many of the
frontend changes are interdependent, it may be possible bring the techmap
changes in under a separate PR.
Declarations within unnamed generate blocks previously encountered issues
because the data declarations were left un-prefixed, breaking proper scoping.
The LRM outlines behavior for generating names for unnamed generate blocks. The
original goal was to add this implicit labelling, but doing so exposed a number
of issues downstream. Additional testing highlighted other closely related scope
resolution issues, which have been fixed. This change also adds support for
block item declarations within unnamed blocks in SystemVerilog mode.
1. Unlabled generate blocks are now implicitly named according to the LRM in
`label_genblks`, which is invoked at the beginning of module elaboration
2. The Verilog parser no longer wraps explicitly named generate blocks in a
synthetic unnamed generate block to avoid creating extra hierarchy levels
where they should not exist
3. The techmap phase now allows special control identifiers to be used outside
of the topmost scope, which is necessary because such wires and cells often
appear in unlabeled generate blocks, which now prefix the declarations within
4. Some techlibs required modifications because they relied on the previous
invalid scope resolution behavior
5. `expand_genblock` has been simplified, now only expanding the outermost
scope, completely deferring the inspection and elaboration of nested scopes;
names are now resolved by looking in the innermost scope and stepping outward
6. Loop variables now always become localparams during unrolling, allowing them
to be resolved and shadowed like any other identifier
7. Identifiers in synthetic function call scopes are now prefixed and resolved
in largely the same manner as other blocks
before: `$func$\func_01$tests/simple/scopes.blk.v:60$5$\blk\x`
after: `\func_01$func$tests/simple/scopes.v:60$5.blk.x`
8. Support identifiers referencing a local generate scope nested more
than 1 level deep, i.e. `B.C.x` while within generate scope `A`, or using a
prefix of a current or parent scope, i.e. `B.C.D.x` while in `A.B`, `A.B.C`,
or `A.B.C.D`
9. Variables can now be declared within unnamed blocks in SystemVerilog mode
Addresses the following issues: 656, 2423, 2493
The only difference between "RTLIL" and "ILANG" is that the latter is
the text representation of the former, as opposed to the in-memory
graph representation. This distinction serves no purpose but confuses
people: it is not obvious that the ILANG backend writes RTLIL graphs.
Passes `write_ilang` and `read_ilang` are provided as aliases to
`write_rtlil` and `read_rtlil` for compatibility.
This parameter will resolve to the name of the cell being mapped. The
first user of this parameter will be synth_intel_alm's Quartus output,
which requires a unique (and preferably descriptive) name passed as
a cell parameter for the memory cells.
The new types include:
- FFs with async reset and enable (`$adffe`, `$_DFFE_[NP][NP][01][NP]_`)
- FFs with sync reset (`$sdff`, `$_SDFF_[NP][NP][01]_`)
- FFs with sync reset and enable, reset priority (`$sdffs`, `$_SDFFE_[NP][NP][01][NP]_`)
- FFs with sync reset and enable, enable priority (`$sdffce`, `$_SDFFCE_[NP][NP][01][NP]_`)
- FFs with async reset, set, and enable (`$dffsre`, `$_DFFSRE_[NP][NP][NP][NP]_`)
- latches with reset or set (`$adlatch`, `$_DLATCH_[NP][NP][01]_`)
The new FF types are not actually used anywhere yet (this is left
for future commits).
Previously this was tagged only with YS_ATTRIBUTE(noreturn), but not
YS_NORETURN, so it got lost in #2173, resulting in warnings in
frontends/ast/simplify.cc:
frontends/ast/simplify.cc:267:1: warning: function declared 'noreturn' should not return [-Winvalid-noreturn]
}
^
frontends/ast/simplify.cc:379:1: warning: function declared 'noreturn' should not return [-Winvalid-noreturn]
}
^
Upgrading to WASI SDK 11.0 caused the WASM build to fail because WASM
does not have signals. (Arguably Yosys was broken even before, it was
just broken silently.)
The $div and $mod cells use truncating division semantics (rounding
towards 0), as defined by e.g. Verilog. Another rounding mode, flooring
(rounding towards negative infinity), can be used in e.g. VHDL. The
new $divfloor cell provides this flooring division.
This commit also fixes the handling of $div in opt_expr, which was
previously optimized as if it was $divfloor.
The $div and $mod cells use truncating division semantics (rounding
towards 0), as defined by e.g. Verilog. Another rounding mode, flooring
(rounding towards negative infinity), can be used in e.g. VHDL. The
new $modfloor cell provides this flooring modulo (also known as "remainder"
in several languages, but this name is ambiguous).
This commit also fixes the handling of $mod in opt_expr, which was
previously optimized as if it was $modfloor.
whitequark
gatecat
Zachary Snow
Rupert Swarbrick
Marcelina Kościelnicka
Claire Xenia Wolf
N. Engelhardt
Miodrag Milanović
Xiretza
Michael Singer
Lofty
Robert Baruch
umarcor
nitz
N. Engelhardt
clairexen
Alberto Gonzalez
Anonymous Maarten